Is there something safe to use, that will not hurt the aluminum fins on the indoor coil, that can be used for preventative maintenace to keep a condensate line from plugging? I would plan on using it when the system says the filter needs to be cleaned which is based on hours of operation.

We woke up about 2:30 this morning to find that our four month old Fujitsu 18RLQ was dripping water on our hardwood floor - not a good thing.

I got the line unplugged by disconnecting the drain line at the sink trap, putting in a short piece of flexible conduit that fit quite nicely into the end of the pipe, and blowing back through the line. I then flushed out the line from the top with about a half gallon of very warm water.

Our house has been remarkably dust free, and when the Fujitsu says to clean the filter, there has been very little to clean. So, I suspect that the installation is less than optimal. Getting the contractor to change the installation from less than optimal to optimal doesn't seem likely.

So, what can I do to keep it from happening again?

Edited to add
Another thought for maintenance- Would disconnecting the drain line at the trap and using a wet/dry vac to clean out the pipe about every two months be better than chemicals?